1. Field of the Invention
The present invention relates generally to support means for supporting a table machine, and more particularly, to a folding support, that allows utilization of the weight of the table machine that is supported on the folding support to share the force necessary for folding the folding support into the received status.
2. Description of the Related Art
FIGS. 1-3 show a conventional mobile table machine stand 2 for supporting a table machine, for example, table saw 1. The mobile table machine stand 2 comprises a platform 3 carrying the table saw 1, a pair of first legs 4 each having one end respectively pivoted to the platform 3 by a pin 2a and connected to a handle 4a and the other end terminating in a bearing portion 4b for touching the floor, a pair of second legs 5 each having one end respectively pivoted to the first legs 4 by a pin 2b and terminating in an extension 5b and the other end mounted with a wheel 5a, and a pair of connecting members 6 each having the two distal ends respectively pivoted to the platform 3 and the extension 5b of the second legs 5 by pins 2c and 2d. By means of the aforesaid arrangement, the mobile table machine stand 2 can be alternately set between the extended position shown in FIG. 1 and the received position shown in FIG. 3.
The design of the aforesaid mobile table machine stand 2 allows utilization of the weight of the table saw 1 to share the force F1 necessary for folding the mobile table machine stand 2 into the received position. However, when the bearing portions 4b of the first legs 4 are stopped at the floor, the table saw 1 is kept in a tilted position, and the center of gravity W of the table saw 1 is offset from the pivot points, i.e. pins 2b, between the first legs 4 and the second legs 5 (see FIG. 2), if the grasp force F2 applied by the user to the handle 4a cannot sustain the downward pressure of the table saw 1, the second legs 5 will be forced to move toward the first legs 4 rapidly, and the elastic force of the springs 7 between the first legs 4 and the second legs 5 will accelerate the movement of the second legs 5 toward the first legs 4, resulting in a potential accident.
Further, when the mobile table machine stand 2 is extended out, the shank 8a of each T-shaped lock member 8 is respectively inserted through a through hole 4c on each first leg 4 and a through hole 9a on a respective locating plate 9 that is respectively welded to each of the second legs 5 to lock the first legs 4 and the second legs 5, preventing movement of the second legs 5 toward the first legs 4. When the mobile machine stand 2 is in the received position, the shanks 8a of the T-shaped lock members 8 are respectively stopped at the extensions 5b of the second legs 5 preventing movement of the second legs 5 relative to the first legs 4. The T-shaped lock members 8 provide a locking function. However, it is difficult to align the through holes 4c of the first legs 4 with the through holes 9a on the locating plates 9 at the second legs 5. Further, the T-shaped lock members 8 must be pulled out of the locking position or pushed into the locking position when extending out or receiving the mobile table machine stand 2. Further, a shearing force may be produced between the first legs 4 and the second legs 5 due to an accidental impact of the mobile table machine stand 2, thereby damaging the T-shaped lock members 8.
Therefore, the aforesaid conventional mobile table machine stand is not satisfactory in function.